Iminocarbocation intermediates were in situ-generated by treating various oximes with trifluoromethanesulfonic anhydride (Tf2O) in the presence of triethylamine in toluene and nucleophilic trapping with amines or sodium enolates under mild conditions afforded the corresponding amidines and enamines. Some of the thus-obtained enamines were converted to 2-substituted 4-oxo-3-quinolinecarboxylic acid derivatives by subsequent intramolecular Friedel–Crafts acylation.
An asymmetric Heck reaction−carbanion capture process was realized for the first time, making possible the catalytic asymmetricsynthesis of various functionalized bicyclo[3.3.0]octane derivatives 6 in up to 94% ee. Sodium bromide had interesting effects on this asymmetric Heck reaction−carbanion capture process, and these effects were useful for improving the enantiomeric excess. Furthermore, the
Stereoselective cycloadditions of chiral acyl-nitroso compounds; synthetically useful reactions of the adducts
作者:Andrew Miller、Garry Procter
DOI:10.1016/s0040-4039(00)94426-5
日期:1990.1
The adducts from the addition of acyl-nitrosocompounds to dienes are shown to undergo reactions which are important for their use in synthesis, via cleavage of the NO bond to produce monocyclic systems followed by further functionalisation.
Reaction paths of 1,3-oxazolinium saltz with stabilized carbanions
作者:Martine Dreme、Pierre Le perchec、Jacques Garapon、Bernard Sillion
DOI:10.1016/s0040-4039(00)97535-x
日期:1982.1
Reaction of stabilizedcarbanions with 3-methyl-2-phenyl-1,3-oxazolinium triflate occurs at both C5 and C2 sites with a regioselectivity depending partially on steric effects. The reaction at C2 site can result in the formation of 1,4-oxazepin derivatives.
Regiochemical directing effects in palladium catalyzed alkylations with polyene electrophilic partners
作者:Barry M Trost、Christopher J Urch、Ming-Hong Hung
DOI:10.1016/s0040-4039(00)85104-7
日期:1986.1
Unusual regioselectivity in alkylations arise as a result of the dynamic behavior of trihapto pentadienyl metal complexes, a phenomenon previously studied from a theoretical point of view.